本文選題：川中地區(qū) + 侏羅系��； 參考：《西南石油大學(xué)》2017年碩士論文

【摘要】：川中龍崗地區(qū)侏羅系沙溪廟組砂體廣泛發(fā)育,但砂體特征及展布規(guī)律不清。為明確河道砂體基本特征及砂體演化過程,結(jié)合野外露頭、巖心觀察、薄片鑒定及測井-地震預(yù)測成果綜合開展研究。研究結(jié)果表明,龍崗地區(qū)沙溪廟組主要為河流-湖泊沉積環(huán)境,可識別出辮狀河、河漫平原、灘壩、泥坪等多個沉積相帶,沙一段河道砂體多屬辮狀河心灘沉積,巖性以灰色、紫紅色粗砂巖為主,少量中粒砂巖及含礫粗砂巖,多呈厚層塊狀砂體產(chǎn)出,總體上成熟度偏低。河道砂體巖石類型以長石巖屑砂巖和巖屑長石砂巖為主。砂巖碎屑顆粒成分以石英為主,次為長石和巖屑。按粒度劃分砂巖以細(xì)砂巖為主,次為中砂巖,分選中等—好,磨圓為次圓狀,顆粒間以點—線接觸為主,顆粒支撐為主,膠結(jié)類型以孔隙式膠結(jié)為主,部分層段發(fā)育綠泥石粘土襯邊,構(gòu)成薄膜式膠結(jié),局部基底式、再生式膠結(jié)。河道砂體儲集空間包括原生孔、次生孔隙以及裂縫,以粒間溶孔、粒內(nèi)溶孔及構(gòu)造縫為主;因中下部長石含量相對較高,粒內(nèi)溶孔相對發(fā)育。河道砂巖孔隙度主要分布在1.5～8%之間(平均值為2.8%),滲透率分布在0.1～1× 10-3μm2之間(平均滲透率為0.3×10-3μm2)。總體具低孔、低滲背景下局部發(fā)育相對高孔儲層(φ6%)的特征�？缀斫Y(jié)構(gòu)具高排驅(qū)壓力、高中值壓力、高汞不飽和體積和最大連通孔喉半徑、中值孔喉半徑小、退汞效率低特征。儲層受沉積和次生溶蝕作用控制明顯,裂縫存在是獲得工業(yè)油氣流的重要條件。在涼高山湖盆萎縮、大范圍湖退背景下,因盆地西部相對抬升,湖盆西部、西南部沉積基底相應(yīng)大范圍上揚,湖水沿近南西～北東向退出。龍崗地區(qū)緊鄰沉積中心,在下部殘留濱-淺湖相沉積基礎(chǔ)上逐漸演變?yōu)榉簽E平原～河流相沉積,河道砂體逐漸發(fā)育。沙一段河道砂體具高幅箱型-鐘形測井響應(yīng)特征,地震剖面顯示為同相軸下拉、透鏡狀,平面上呈條帶狀分布。砂體寬約390～3440m(平均1170.8m),厚約4～33.75mm(平均13.74m),寬厚比為26:1～312:1(平均106:1)。由沙一段底部向上200m范圍內(nèi)共發(fā)育五期河道,河道砂體平面變化頻繁。河道砂體幾何參數(shù)定量分析表明,龍崗沙一段河道屬低彎度(平均彎度1.044)辮狀河,河道寬約0.6～2.8km,受北東向物源影響導(dǎo)致平面擺動頻繁,除第三期河道受間歇性物源供給不足外,其余幾期河道砂體總體表現(xiàn)為逐漸發(fā)育的規(guī)律。龍崗地區(qū)沙溪廟組底部向上100～200m范圍內(nèi)河道砂體展布范圍和發(fā)育程度達到最大,砂體在龍崗中部龍崗9井區(qū)最為發(fā)育,連通性較好,與斷層或裂縫形成良好搭配關(guān)系有利于油氣的富集成藏。
[Abstract]:The sand bodies of Shaximiao formation of Jurassic system in Longgang area of central Sichuan are widely developed, but the characteristics and distribution of sand bodies are unclear. In order to clarify the basic characteristics and evolution process of channel sand body, combined with field outcrop, core observation, slice identification and logging and seismic prediction results, a comprehensive study was carried out. The results show that the Shaximiao formation in Longgang area is mainly fluvial and lacustrine sedimentary environment, and many sedimentary facies belts such as braided river, Manhe plain, beach dam, mud flat and so on can be identified. The sand bodies of the channel in the first section of the sand are mostly braided river core beach deposits, and the lithology is gray. The purplish red coarse sandstone, a small amount of medium-grained sandstone and gravel-bearing coarse sandstone, is mostly produced by thick layer massive sand bodies, and the maturity is low on the whole. The main rock types of channel sand body are feldspar lithic sandstone and lithic feldspar sandstone. The grain composition of sandstone clastic is mainly quartz, followed by feldspar and lithic. According to the granularity, the sandstone is mainly fine sandstone, the second is middle sandstone, the separation is medium good, the grinding circle is subcircular, the grain is mainly point-line contact, the grain support is the main, and the cementation type is mainly pore cementation. Chlorite clay lining formed thin film cementing, local substrate cementation and regenerative cementation in some layers. The reservoir space of channel sand body consists of primary pore, secondary pore and fracture, mainly intergranular dissolved pore, intragranular dissolved pore and structural joint, because of the relatively high content of feldspar in the middle and lower part, the intragranular dissolution pore is relatively developed. The porosity of channel sandstone is mainly between 1.5% and 8% (average value is 2.8%), and permeability is between 0.1 脳 10 -3 渭 m 2 (average permeability 0.3 脳 10 -3 渭 m 2). Under the background of low porosity and low permeability, relatively high porosity reservoirs (蠁 6) are developed locally. The pore throat structure is characterized by high displacement pressure, high unsaturated volume of mercury, maximum connected radius of pore throat, small radius of median pore throat and low efficiency of mercury removal. The reservoir is obviously controlled by sedimentation and secondary dissolution, and the existence of fractures is an important condition for obtaining industrial oil flow. Under the background of the atrophy of the Liangshan lake basin and the large-scale lake retreat, because of the relative uplift in the western part of the basin, the sedimentary basement in the western part of the lake basin and the southwestern part of the lake basin rise in a large scale, and the lake water exits from the lake along the near south-west to the north. The Longgang area is adjacent to the sedimentary center, and on the basis of the residual shore-shallow lacustrine facies in the lower part, it gradually evolves into the flood plain ~ fluvial facies, and the channel sand body develops gradually. The channel sand body of the first member of the Shahejie formation is characterized by a high-amplitude box-bell-shaped logging response. The seismic profile shows a cophase axial pull-down, a lenticular shape, and a strip distribution on the plane. The width of the sand body is about 390m (mean 1170.8mg), the thickness of the sand is about 40.75mm (mean 13.74mg), the ratio of width to thickness is 26: 1 / 312: 1 (mean 106: 1). From the bottom of the first section of sand to 200 m above, there are five stages of river channel, and the plane of channel sand body changes frequently. The quantitative analysis of the geometric parameters of the channel sand body shows that the channel in Longgang sand section is a braided river with low bend (mean curve 1.044), and the channel width is about 0.6 ~ 2.8km. the plane swinging frequently due to the influence of the north-east source, except for the lack of intermittent material supply in the third stage of the channel. The other several periods of river channel sand body overall performance is the law of gradual development. At the bottom of Shaximiao formation in Longgang area, the distribution and development degree of channel sand body reaches the maximum within 100 ~ 200m above the bottom, and the sand body is the most developed in Longgang 9 well area in the middle of Longgang, and the connectivity is good. A good collocation with faults or fractures is beneficial to oil and gas rich integrated reservoirs.
【學(xué)位授予單位】：西南石油大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P618.13

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